1. Field of the Invention
The present invention relates to conveying apparatus and, more particularly, is directed to conveying apparatus used in connection with mobile articulated conveyors and their attendant stationary conveyors for conveying mined materials within a mine.
2. Description of the Invention Background
In typical underground mining operations, such as in coal mining or the like, belt conveyors are generally used to transport the mined coal out of the mine. In particular, during the early stages of the mine development, main haulageways are developed within the mine to accommodate stationary main belt conveyors that are used to transfer the mined coal out of the mine or to storage areas known as bunkers. As the mine development progresses, roadways are branched off from the main haulageways to lesser roadways and finally to rooms which are generated specifically to retrieve the remaining coal. Although the mine layout and development is somewhat dictated by the configuration of the particular seam, the roadways are typically developed perpendicular to the main haulageway. As the lesser roadways are developed, separate stationary conveyors, known as panel conveyors, are installed therein to convey the mined coal to the main belt conveyor located in the main haulageway.
In a preferred practice, a mobile conveyor may be used to convey the mined ore directly from the mining machine to one of the corresponding stationary conveyors located remote from the mining machine. Mobile articulated conveyors of the types disclosed in U.S. Pat. Nos. 4,031,997 and 4,852,724 can move under self-propulsion along mine roadways and around corners while receiving the mined ore directly from the mining machine and discharging it onto the main conveyor or one of its attending panel conveyors. Mobile articulated conveyors generally employ two different methods of discharging the mined ore onto an attending stationary conveyor. More specifically, the mobile articulated conveyor may be adapted to tram onto a track mounted directly above the stationary conveyor or, in the alternative, it may be adapted to tram beside the stationary conveyor and employ a separate belt conveyor, known as a bridge conveyor, to transfer the coal from the discharge end of the mobile articulated conveyor to the stationary conveyor. A problem with the first such arrangement exists if insufficient height is available to accommodate such "stacked" apparatus.
One problem which exists with the latter discharge method is that of effecting a transition from discharging particulate material from the bridge conveyor onto the panel conveyor from a previous discharge position onto the main conveyor. Specifically, because the discharge end of the bridge conveyor rides upon guide means attached to the stationary conveyor and because the discharge end of the mobile articulated conveyor is also partially supported and guided by the stationary conveyor, a certain length of the discharge end of the articulated conveyor is constrained to remain parallel with the stationary conveyor. Therefore, the length that can be mined away from the stationary conveyor will always be shorter than the combined length of the mobile articulated conveyor and the miner itself. As such, aforementioned length of the articulated conveyor cannot be disconnected from the stationary conveyor because the mobile articulated conveyor cannot be accommodated within the length of tunnel that can be mined while being so constrained.
Further, because the mobile conveyor's discharge follows a path which is not at a 90 degree angle, but rather "cuts the corner" on a fixed radius between the main and panel conveyor belts, at the juncture between the belts, there is no means provided for receiving the bridge conveyor's discharge which does not follow a 90 degree path in the horizontal plane. Accordingly, one practice which is employed is to allow the miner to proceed in advance of the flexible conveyor and, instead, use shuttle cars to convey mined materials from an advance area sufficient to allow the length of the articulated conveyor to be accommodated. However, in that method an additional piece of expensive machinery is needed.
Thus, the need exists for an auxiliary coal conveying apparatus that can be used in connection with stationary conveyors to enable a mining machine and its attendant mobile articulated conveyor to allow continuous mine development without the need for additional mining machinery.